*Definition [#gcf5eab3]
-A set is said to be degenerate if it is vacuous or contains a single point.

*Reference [#m04a3dd9]
-J.W.T Youngs, ''A note on separation axioms and their application in the theory of locally connected topological spaces.'', Bull. Amer. Math. Soc. 49 (1943), 383-385.